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The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Climate Change Scenarios
Dr. Elaine Barrow
Canadian Climate Impacts Scenarios (CCIS) Project
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
What is a scenario?
“…a coherent, internally consistent and plausible description of a possible future state of the world…”[Parry & Carter, 1998]
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Scenario Terms• Emissions scenarios• Projections• Climate Change Scenarios• Climate Scenarios
“…a plausible future climate that has been constructed for explicit use in investigating the potential consequences of anthropogenic climate change…”
[IPCC TAR, 2001]
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Why do we need scenarios?
• To provide data for VIA assessment studies• To act as an awareness-raising devices• To aid strategic planning and/or policy
formation• To scope the range of plausible futures• To structure our knowledge (or ignorance) of
the future• To explore the implications of decisions
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
What are the challenges of developing climate change scenarios?
• simple to obtain, interpret and apply• provide sufficient information for VIA assessments• physically plausible and spatially compatible• consistent with the broad range of global warming
projections• reflect the potential range of future regional climate
change, i.e., be representative of the range of uncertainty in projections
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
What sort of information does the VIA community require?
Typically:• Daily, monthly or seasonal temporal resolution
• Site, regional to continental scales• Single and/or multiple climate variables
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Scenario Needs
1. Which climate variables?
2. How many scenarios?
3. Local data for case studies/sites, or national/regional coverage?
4. Spatial resolution - 300km, 100km, 50km, 10km, 1km? Can this choice be justified?
5. Changes in average climate, and/or changes in variability?
6. Daily or monthly changes?
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Three ways ... COMPLEXITY
• Incremental (arbitrary, synthetic) scenarios
• Analogue scenarios
• Scenarios from global climate models (GCMs)
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Incremental Scenarios
4
6
8
10
12
1961
1963
1965
1967
1969
1971
1973
1975
1977
1979
1981
1983
1985
1987
1989
Year
Mea
n an
nual
tem
pera
ture
(°C
)
∆T=2°CClimate change scenario
Observed time series
Climate scenario
Can provide valuable information about:• sensitivity• thresholds or discontinuities of response• tolerable climate change
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
ADVANTAGES: simple to construct and apply, allow relative sensitivity of impacts sectors/models to be explored
DISADVANTAGES: arbitrary (and unrealistic) changes, may be inconsistent with uncertainty range
Yield change (t/ha) of Valencia orange in response to changing temperature and CO2 concentration [Source: Rosenzweig et al. (1996)]
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Analogue ScenariosIdentification of recorded climate regimes which may resemble the future climate in a
given regionAssumption: climate will respond in the same way to a unit change in forcing despite its source and even if boundary conditions differ
Spatial
Temporal
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Spatial Analogues
Identify regions which today have a climate analogous to that anticipated in the study region in the future
[Source: Parry & Carter, 1988]
• Approach restricted by frequent lack of correspondence between other non-climatic features of the two regions
• Causes of the analogue climate likely different from the causes of future climate change
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Temporal Analogues: PalaeoclimaticUse information from the geological record -fossils, sedimentary deposits - to reconstruct past climates
• mid-Holocene, 5-6k BP, 1°C warmer
• last (Eemian) interglacial, 125k BP, approx. 2°C warmer
• Pliocene, 3-4m BP, 3-4°C warmer
IPCC, 1990
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Palaeoclimatic Analogues• changes in the past unlikely to have been
caused by increased GHG concentrations• data and resolution generally insufficient,
i.e., extremely unlikely to get daily resolution and individual site information
• uncertainty about the quality of palaeoclimatic reconstructions
• higher resolution (and most recent) data generally lie at the low end of the range of anticipated future climatic warming
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Instrumental AnaloguesPast periods of observed global- or hemispheric-scale warmth used as an analogue for the future
Difference =0.4°C
Northern Hemisphere temperature record
Lough et al., 1983
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Instrumental AnaloguesThe 1930s in the North American Great Plains have frequently
been used as an analogue for the future.
Mean temperature (°C)
Precipitation (mm)
Differences between 1931-1940 average and 1951-1980 average in the MINK states (Easterling et al., 1992)
State Winter (DJF) Spring (MAM) Summer (JJA) Autumn (SON) AnnualMissouri 1951-1980 51 100 97 82 989
1930s ∆ +16 -23 -21 -1 -28Iowa 1951-1980 26 79 106 61 815
1930s ∆ +6 -53 -28 +16 -60Nebraska 1951-1980 14 60 79 35 566
1930s ∆ +4 -23 -54 -21 -93Kansas 1951-1980 19 67 88 54 684
1930s ∆ 0 -19 -59 -24 -102
State Winter (DJF) Spring (MAM) Summer (JJA) Autumn (SON) AnnualMissouri 1951-1980 0.3 12.7 29.4 13.9 12.8
1930s ∆ +1.0 0.0 +1.1 +0.6 +0.7Iowa 1951-1980 -5.7 8.9 22.3 10.6 9.0
1930s ∆ +1.1 +0.3 +1.2 +0.6 +0.8Nebraska 1951-1980 -3.6 8.9 22.6 10.5 9.6
1930s ∆ +0.6 +0.7 +1.6 +1.0 +1.0Kansas 1951-1980 0.1 12.1 25.2 13.6 12.8
1930s ∆ +0.9 +0.6 +1.3 +1.0 +0.9
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Instrumental Analogues
Palmer Drought Severity Index (PSDI) for the US Corn Belt, 1930-1980.
[Source: Rosenberg et al., 1993]
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Instrumental AnaloguesRice-growing areas in Japan
0.4°C warmer than base
Base, 1951-1980 Warm decade, 1921-1930Climate scenario
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Instrumental AnaloguesADVANTAGES• data available on a daily and local scale• scenario changes in climate actually observed and
so are internally consistent and physically plausible
DISADVANTAGES• climate anomalies during the past century have been
fairly minor cf. anticipated future changes• anomalies probably associated with naturally-
occurring changes in atmospheric circulation rather than changes in GHG concentrations
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Scenarios from GCMs
GCMs are the“…only credible tools currently available for
simulating the physical processes
that determine global climate...”
[IPCC]
[Source: David Viner, UK Climate Impacts LINK Project]
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
GCM evolution1980s EQUILIBRIUM EXPERIMENTS
late 1980s TRANSIENT EXPERIMENTS‘COLD’ START
early 1990s ‘WARM’ START
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
-0.6
-0.5
-0.4-0.3
-0.2
-0.1
0.0
0.1
0.2
0.30.4
0.5
0.6
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
Glo
bal-m
ean
tem
pera
ture
cha
nge
(°C
) wrt
196
1-19
90 Warm start GCMs
Projection of future climate (model output)
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Natural Forcing Only
[Source: IPCC TAR]
Anthropogenic Forcing OnlyAll Forcings
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
IPCC Special Report on Emissions Scenarios (2000)
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Emissions scenarios
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Climate change scenario
1.4-5.8°C
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Which GCM(s)?
• Vintage• Resolution• Validity• Representativeness of results
[Source: Smith and Hulme, 1998]
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Spatial Scale of ScenariosEffect of scenario resolution on impact outcome
[Source: IPCC, WGI, Chapter 13]
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
IPCC-TGCIA Criteria
• fully-coupled ocean-atmosphere GCMs• documented in the peer reviewed
literature• performed a multi-century control run• participated in CMIP2
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
GCMs meeting IPCC-TGCIA criteria
• Canadian Centre for Climate Modelling and Analysis (CGCM1, CGCM2)
• Hadley Centre for Climate Prediction and Research (HadCM2, HadCM3)
• Australian Commonwealth Scientific and Industrial Research Organisation (CSIROMk2b)
• German Climate Research Centre (ECHAM4)• Geophysical Fluid Dynamics Laboratory (GFDL-R15,
GFDL-R30)• Japanese Centre for Climate Research Studies
(CCSR/NIES)• US National Centre for Atmospheric Research (NCAR-PCM)
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
t2
t1
Climate change experiment
Time
Glo
bal m
ean
tem
pera
ture
(°C
)But GCMs are not accurate, so we cannot
use their output directly ...
Climate change scenario
t1 is typically 1961-1990t2 is a future time period, e.g., 2040-2069, representing the 2050s
∆T=t2-t1
Some models exhibit large inter-decadal variability, so average over 30 years to capture longer-term trend.
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Temperature change (°C)
Climate change scenario
0
1
2
3
4
5
6
J F M A M J J A S O N D
Month
Mea
n te
mpe
ratu
re c
hang
e (°
C)
Climate change scenario
-20-15-10-505
10152025
J F M A M J J A S O N DMonth
Mea
n t
emp
erat
ure
(°C
)
Climate scenarios
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Scatter PlotsCooler, wetter
Cooler, drier
Warmer, wetter
Warmer, drier
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
-20
-10
0
10
20
30
40
-2 -1 0 1 2 3 4 5 6 7 8
Mean temperature change (°C)
Prec
ipita
tion
chan
ge (%
)‘Natural’ climate variability
The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related
information to the VIA community in Canada
Key Points
Scenarios should:• be internally consistent, physically
plausible and spatially compatible• address the range of uncertainty• provide, as far as is possible, climate
information at the scales required by the VIA community
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